Three-position valve



March 2 1962 J. w. BLAIR 3,026,908

THREE-POSITION VALVE Filed July 9, 1958 2 Sheets-Sheet 1 46 Q 50 p .5452 i 42 46 ATMOS PH ERIC PORT CONTROL LINE.

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VACUUM LINE INVENTOR.

.J HN w. BLAIK; T E

March 27, 1962 J. w. BLAIR 3,026,908

THREE-POSITION VALVE Filed July 9, 1958 2 Sheets-Sheet 2 INVENTOR.

0' JOHN w. BLAIR BY 31 E 4: fiAz/laam 6? 3,026,908 THREE-POSITION VALVEJohn W. Blair, South Bend, Ind, assignor to The Bendix Corporation, acorporation of Delaware Filed July 9, 1958, Ser. No. 747,524 Claims.(Cl. 137-6275) The present invention relates, as indicated, tothreeposition valves; and more particularly to a simplified form ofvalve construction wherein a first pressure port is communicated to itscontrol port in one position of its operating handle, a second pressureport is communicated to the control port in a second position of itsoperating handle, and wherein both first and second ports are isolatedfrom the control port in a third position of its operating handle.

An object of the present invention is the provision of a new andimproved Valve construction of the above described type which is simplein design, rugged in construction, and inexpensive to manufacture.

Another object of the invention is the provision of a new and improvedvalve construction of the type having a single poppet member forcontrolling communication between one of its pressure ports and itscontrol port, and a tubular member having a tubular flow conductingprojection for projecting through the control chamber into engagementwith the poppet member for conducting the second source of pressure tothe control chamber and which is valved off when the tubular projectionabuts the poppet member, a cam follower connected to the tubular memberthrough a connection having predetermined =lost motion, and a cam memberhaving three surfaces each of which corresponds with a position of thevalve and the intermediate surface of which centers the lost motionconnection While the tubular member is in abutment with the poppetmember, and a spring which biases the tubular member into engagementwith the poppet member with a generally predetermined force when the cammember holds the lost motion connection in its centered position.

The invention resides in certain constructions and combinations andarrangements of parts, and further objects and advantages of theinvention will become apparent to those skilled in the art to which theinvention relates from the following description of the preferredembodiments described with reference to the accompanying drawingsforming a part of this specification, and in which:

FIGURE 1 is a longitudinal cross sectional view of one embodiment of theinvention;

FIGURE 2 is an enlarged fragmentary cross sectional view of a portion ofthe valve structure shown in FIG- URE 1;

FIGURE 3 is a longitudinal cross sectional view of a second embodimentof the invention; and

FIGURE 4 is an enlarged fragmentary cross sectional view of a portion ofthe valve structure shown in H6- URE 3.

The valve construction of the present invention will have utility in anynon-modulating valve service wherein either one of two pressure sourcesare to be communicated individually to an outlet or control port, andwherein there must also be provided a shut-oft position wherein both ofthe pressure sources must be valved off from the outlet or control port.As an indication of one application in which the valve will havedefinite advantages, reference may be had to my copending applicationSerial No. 706,456, filed December 31, 1957, now abandoned. Referringnow to the drawings, the valve shown in FIG- URE 1 generally comprises abody member 10 having an axially extending chamber 14 therein of apredetermined 3,026,903 Patented Mar. 27, 1962 "the diameter 12 in itsupper end, and a larger diameter portion 16 adjacent its lower end,which chambers are connected by a small diameter passage or port 13 toform a shoulder or valve seat 20 in the chamber 16. A valve closure orpoppet member 22 is provided in the lower chamber 16 and is biased intoengagement with the seat 20* by a relatively stifi' coil spring 24 thatis positioned between the poppet member 22 and a pipe adapter 26 screwedinto the bottom end of the lower chamber 16. A control port 28communicates with the longitudinally extending chamber 14- immediatelyabove the valve seat 20, and a generally tubularly-shaped valve member34) is positioned in the chamber 14 in a manner to provide a suitableseal with the portions of the chamber 14 upwardly of the control portas. An atmospheric port 32 is provided in the body member adjacent theupper end of the generally tubularly-shaped valve member 30, and thegenerally tubularly-shaped valve member 36 is provided with a reduceddiameter tubular portion 34 adapted to extend through the valve port 18into engagement with the poppet member 22. The central opening 36 of thetubular member 39 extends throughout its length, and the upper end ofthe tubular member is milled out to provide a bifurcated portion havinga slot 38 adapted to receive the tongue 4d of a cylindrically shaped camfollower member 42 that is positioned in the upper end of the valvechamber 14. A slotted hole 44 is provided in each of the legs of thebifurcated portion of the tubular valve member 30, and each holereceives a respective end of a pin 46 that is carried by the tongue ofthe cam follower member 42. The pin 46 is adapted to normally be heldcentrally in the elongated hole or slot 44 by a cam member 48 when thecam member 48 is the intermediate or valve closed position shown in thedrawmg.

In the embodiment shown in FIGURE 1, the cam member 48 is formed bymeans of a pivoted lever that is pinned to the body member adjacent theupper end of the cam follower member 42, and which lever is providedwith three surfaces 54), 52 and 54 respectively arranged atprogressively greater distances from the pivotal axis of the lever orcam member 48. The intermediate surface 52 of the cam member 48 and thecam follower member 42 are so arranged relative to the lost motionconnection, as provided by the slotted holes 44 and pin 46, so as tocentrally locate the pin 46 in the slotted holes 44 when the lower endof the tubular valve member 3% is in abutment or engagement with thepoppet member 22. A suitable coil spring 56 is positioned between thetubular valve member 36 and the cam follower member 42 to urge themembers in opposite directions and thereby hold the cam follower member42 in engagement with the cam member 48 and at the same time hold thetubular valve member 36 in engagement with the poppet member 22.

The first coil spring 24 will normally be made stronger than is the coilspring 56 so that the coil spring 56 will not bias the poppet member 22away from its shoulder or valve seat 2% when the pin is centered in theslotted holes 44. There is thereby provided a generally predeterminedpositive force tending to hold the tubular member 3t into engagementwith the poppet member 22, which force is less than that force holdingthe poppet member 22 into engagement with its valve seat 2i to therebyprovide the closed position of the valve.

When the handle 48 is rotated to its position wherein the first surfaceis brought into position for engagement with the cam follower 42,suflicient clearance will exist between the cam member 48 and the camfollower member 42 to permit the pin 46 to move into engagement with theupper end of the slotted holes 44, under the action of coil spring 56,to cause the cam follower member 42 and the tubular member 30 to assumetheir expanded condition. A third coil spring 58 is provided between thebody member and the tubular valve member 30 to move the tubular valvemember and the cam follower member 42 upwardly as a unit after the pin46 goes solid with the upper end of the slotted holes 44 to thereby drawthe lower end 34 of the tubular valve member 39 out of engagement withthe poppet member 22. In this position, therefore, atmospheric pressurefrom the port 32 will be communicated through the central opening 36 ofthe tubular valve member to the control port 28 to thereby provide thefirst operating position of the valve structure.

When the handle 48 is moved out of its right hand or first operatingposition above described to its vertical position, the tubular valvemember 30 will be moved downwardly into engagement with the poppetmember 22 to provide the valve closed position also previouslydescribed; and when the handle 48 is moved into its left hand positionto bring the flat cam surface 54 into engagement with the cam follower42, the cam follower member will be moved downwardly sufficiently tocause the pin 46 to go solid with the lower end of the slotted holes 44and thereby positively move the tubular valve member 30 still furtherdownwardly to lift the poppet member 22 out of engagement with its valveseat 20. In this position, therefore, communication between theatmospheric port 32 and the control port 36 will be closed off, whilecommunication between the lower chamber 16 and the control port 28 willbe opened. In this position of the valve, therefore, the pressure whichis supplied to the chamber 16 (which in this case is vacuum) is suppliedto the control port 28 of the valve.

It will be apparent that pressures other than atmospheric pressure canbe supplied to the port 32 provided suitable sealing means is usedbetween the cam follower member '42 and the axially extending chamber12; and that pressure levels other than vacuum can be supplied to thelower chamber portion 16, so that the valve may be used to alternatelycommunicate substantially any pressure levels which differ from eachother to a control port. In this regard, the pressure forces exerted onthe cam follower member, the tubular valve member and the poppet membermust be taken into consideration when sizing the various springs so thatthere will be a positive sealing force insufficient to lift the poppetmember 22 from its seat when the valve is in its centered or closedposition, and the tubular valve member is in engagement with the poppetmember.

The embodiment shown in FIGURE 3 of the drawings is similar in manyrespects to the embodiment shown in FIGURE 1, and differs principally inthe spring and camming arrangement used to actuate the valve. Thosevalve portions of FIGURE 3 which have corresponding parts in FIGURE 1will be designated by a like reference numeral, and will becharacterized further in that a prime mark is aflixed thereto. In theembodiment shown in FIGURE 3 the body member 10' is slightly elongatedover that shown in FIGURE 1 so as to provide a longer valve chamber 14'than that shown in FIGURE 1. The camming member 48' of the presentembodiment is shaped somewhat differently than the cam member of theembodiment shown in FIGURE 1, and differs further in that it ispositioned beneath the cam follower member 42 so as to at all timespositively bias the cam follower member 42 away from the tubular valvemember 30'. The cam member 48 of the present embodiment is formed bymeans of a transverse shaft 60 which extends through an opening 64 inthe tongue 40' and which has a pair of laterally spaced camming surfaces62 formed integrally thereon which straddle the tongue 40'. One end ofthe shaft 60 is suitably journalled in an opening 66 in the sidewalls ofthe body member and the other end of the shaft is journalled in athreaded plug 68 that is threaded 4 into an opening 70 in the oppositeside of the body member 10'.

In the center or valve closing position of the lever 48, the pin 46 willbe centrally located in the slotted holes 44', as was the structure ofthe previous embodiment; and in the present embodiment the tubular valvemember 30' is held into sealing engagement with the poppet 22 by a coilspring 76 positioned between the tubular valve 30 and a washer 78 whichbears against the bottom surface of the shaft 60. When the lever 48 isrotated to its first position to bring the cam surfaces 54' intoengagement with the bottom surface of the cam follower member 42, thepin 46' will be moved into engagement with the upper end of the slottedopenings 44 to lift the bottom end of the tubular valve member 30 clearof the poppet member 22. Fluid flow is thereby established between thepressure port 32 and the control port 28. When the handle 48 is movedinto its center position, camming surface 52 will be in engagement withthe bottom surfaces of the cam follower member 42' to cause the tubularvalve member 30 to be in engagement with the poppet member 22 aspreviously indicated. When the control handle 48 is moved into its thirdposition, wherein the camming surfaces 50 are brought into engagementwith the cam follower 42, the pin 46 will be in engagement with thebottom end of the slotted holes 44' and sufiicient force Will beprovided by the springs 72 and 76 to cause the tubular valve member 30to lift the poppet member 22' out of engagement with its valve seat 20'.In this third position-of the valve, full communication will be providedbetween the bottom valve chamber 16' and the control port 28 as was donein the previously described embodi ment.

While several embodiments of the invention have been shown and describedin considerable detail, I do not wish to be limited to the particularconstructions shown and described; and it is my intention to coverhereby all novel adaptations, modifications and arrangements thereofwhich come within the practice of those skilled in the art to which theinvention relates.

I claim:

1. In a three position valve: a body member having an axially extendingvalve chamber therein that forms an axially extending valve port one endof which is surrounded by a first annular valve seat; a poppet memberfor abutment with said valve seat; a tubular flow conducting memberhaving a first portion of a large cross section that is in slidingsealing engagement with the sidewalls of said valve chamber and agenerally tubular second portion which ends in a second annular valveseat having a considerably smaller cross sectional area than that ofsaid first portion, said second portion being adapted to project throughsaid valve port into engagement with said poppet member; said bodymember having first passage means for communicating with the inside ofsaid tubular member, second passage means for conducting flow from theportion of said chamber positioned between said first valve seat andsaid sliding sealing first portion of said tubular member, and thirdpassage means which communicates with the portion of said valve chamberon the opposite side of said valve port; a cam follower operativelyconnected to said tubular member by means of a lost motion connectionproviding a generally predetermined amount of lost motion between saidcam follower and said tubular member, said cam follower having a firstposition relative to said body member wherein said lost motionconnection is in its expanded abutting condition to transmit abutmentforce from said cam follower to said tubular member causing it to belifted clear of said poppet member, a third position wherein said lostmotion connection is in its contracted abutting condition to transmitabutment force from said cam follower to said tubular member causing itto abut and lift said poppet member from said first valve seat, and anintermediate position wherein said tubular memsaid poppet member fromits valve seat; and a three position cam for moving said cam followerinto its three positions. v

2. In a three position valve: a body member having an axially extendingvalve chamber therein that forms an axially extending valve port one endof which is surrounded by a first annular valve seat; a poppet memberfor abutment with said valve seat; a tubular fiow conducting memberhaving a first portion of a large cross section that is in slidingsealing engagement with the sidewalls of said valve chamber and agenerally tubular second portion which ends in a second annular valveseat having a considerably smaller cross sectional area than that ofsaid first portion, said second portion being adapted to project throughsaid valve port into engagement with said poppet member; said bodymember having first passage means communicating with the inside of saidtubular member, second passage means for conducting flow from theportion of said chamber positioned between said first valve seat andsaid sliding sealing first portion of said tubular member, and thirdpassage means which communicates with the portion of said valve chamberon the opposite side of said valve port; a cam follower operativelyconnected to said tubular member by means of a lost motion connectionproviding a generally predetermined amount of lost motion between saidcam follower and said tubular member, said cam follower having a firstposition relative to said body member wherein said lost motionconnection is in its expanded abutting condition to transmit abutmentforce from said cam follower to said tubular member causing it to belifted clear of said poppet member, -a third position wherein said lostmotion connection is in its contracted abutting condition to transmitabutment force from said cam follower to said tubular member causing itto abut and lift said poppet member from said first valve seat, and anintermediate position wherein said tubular member engages said poppetmember while it is in engagement with said first seat and said lostmotion connection is in an intermediate position where it does nottransmit direct abutment force in either direction; a cam member forforcing said cam follower toward said tubular member and cap-able ofmoving said cam follower from its first through its third positions;first means biasing said poppet member against said first seat, secondmeans biasing said tubular member away from said poppet member; andthird means biasing said cam follower and tubular member apart toprovide said expanded condition of said lost motion connection and toalso hold said cam follower into engagement with said cam member, saidthird means being stronger than said second means.

3. In a three position valve: a body member having an axially extendingvalve chamber therein that forms an axially extending valve port one endof which is surrounded by a first annular valve seat; a poppet memberfor abutment with said valve seat; a tubular flow conducting memberhaving a first portion of a large cross section that is in slidingsealing engagement with the sidewalls of said valve chamber and agenerally tubular second portion which ends in a second annular valveseat having a considerably smaller cross sectional area than that ofsaid first portion, said second portion being adapted to project throughsaid valve port into engagement with said poppet member; said bodymember having first passage means communicating with the inside of saidtubular member, second passage means for conducting flow from theportion of said chamber positioned between said first valve seat andsaid sliding sealing first portion of said tubular member, and a thirdpassage means which communicates with the portion of said valve chamberon the opposite side of said poppet member from said valve port; a camfollower operatively connected to said tubular member by means of a lostmotion connection providing a generally predetermined amount of lostmotion between said cam follower and said tubular member, said camfollower having a first position relative to said body member whereinsaid l-ost motion connection is in its expanded abutting condition totransmit abutment force from said cam follower to said tubular membercausing it to be lifted clear of said poppet member, a third positionwherein said lost motion connection is in its contracted abuttingcondition to transmit abutment force from said cam follower to saidtubular member causing it to abut and lift said poppet member from saidfirst valve seat, and an intermediate position wherein said tubularmember engages said poppet member while it is in engagement with saidfirst seat and said lost motion connection is in an intermediateposition where it does not transmit abutment force in either direction;a cam member for forcing said cam follower away from said tubular memberand capable of moving said cam from its third to its first position;first means biasing said poppet member against said first seat; secondmeans biasing said tubular member toward said poppet member; and thirdmeans biasing said cam follower toward said poppet member to providesaid contracted condition of said lost motion connection and to holdsaid cam follower into engagement with said cam member, said first meansbeing stronger than said second means, and said second and third meanstogether being stronger than said first means.

4. In a three position valve: a body member having an axially extendingvalve chamber therein the sidewalls of which are provided with ashoulder which faces in one axial direction of said chamber, a poppetmember spaced in said one axial direction from said shoulder forabutment therewith, a first spring biasing said poppet member towardsaid shoulder, a generally tubular member positioned in the oppositeaxial direction from said shoulder, said generally tubular member havinga first portion of large cross section in sliding sealing engagementwith the sidewalls of said chamber and having a second generally tubularportion which ends in an annular valve seat for abutment with saidpoppet member, said annular valve seat having a considerably smallercross sectional area than that of said first portion, said body memberhaving first passage means communicating with the central opening ofsaid tubular member, second passage means for conducting fiow from theportion of said chamber positioned between said shoulder and saidsliding sealing first portion of said tubular member, and third passagemeans which communicates with the portion of said valve chamberpositioned in said one axial direction from said shoulder, a camfollower member positioned in said opposite axial direction from saidtubular member and having first, intermediate and third positions, saidcam follower and said tubular member having a lost motion connectionformed by an axial slot in one of the members and a pin carried by theother of the members and extending through said slot, said pin beinggenerally centered in said slot when said tubular member abuts saidpoppet member and said poppet member is in engagement with said shoulderand abutting the ends of said slot in the first and third positions ofsaid cam follower, a second spring biasing said tubular member and camfollower member apart, a third spring biasing said tubular member awayfrom said poppet member, said second spring being stronger than saidthird spring, and a cam member arranged to contact and move said camfollower toward said poppet member through said three positions.

5. In a three position valve: a body member having an axially extendingvalve chamber therein the sidewalls of which are provided with ashoulder which faces in one axial direction of said chamber, a poppetmember spaced in said one axial direction from said shoulder forabutment therewith, a first spring biasing said poppet member towardsaid shoulder, a generally tubular member positioned in the oppositeaxial direction from said shoulder, said generally tubular member havinga first position of large cross section in sliding sealing engagementwith the sidewalls of said chamber and having a second generally tubularportion which ends in an annular valve seat for abutment with saidpoppet member, said annular valve seat having a considerably smallercross sectional area than that of said first portion, said body memberhaving first passage means communicating with the central opening ofsaid tubular member, second passage means for conducting flow from theportion of said chamber positioned between said shoulder and saidsliding sealing first portion of said tubular member, and third passagemeans which communicates with the portion of said valve chamberpositioned in said one axial direction from said shoulder, a camfollower member positioned in said opposite axial direction from saidtubular member and having first, intermediate and third positions, saidcam follower and said tubular member having a lost motion connectionformed by an axial slot in one of the members and a pin carried by theother of the members and extending through said slot, said pin beinggenerally centered in said slot when said cam follower is in itsintermediate position in which said tubular member abuts said poppetmember and said poppet member is in engagement with said shoulder andabutting the ends of said slot in the first and third positions of saidcam follower, a second spring biasing said cam follower to its thirdposition spaced toward said tubular member, a third spring biasing saidtubular member toward said poppet member, said first spring beingstronger than said third spring and the combined force of said secondand third springs being greater than that of said first spring, and acam member arranged to contact and move said cam follower away from saidtubular member from said third position through said first position.

References Cited in the file of this patent UNITED STATES PATENTS1,707,040 Belknap Mar. 26, 1929 1,721,349 Mitton July 16, 1929 1,747,910Sieforth Feb. 18, 1930 1,814,565 Lombard July 14, 1931 1,925,610 ShinnSept, 5, 1933 2,171,316 Sittert Aug. 29, 1939 2,766,772 Welty Oct. 16,1956 2,841,178 Schultz July 1, 1958 2,854,239 Schnell Sept. 30, 1958FOREIGN PATENTS 683,127 France of 1930

